The Frequency of Intraventricular Hemorrhage and its Risk Factors in Premature Neonates in a Hospital’s NICU

Objective Intra-ventricular hemorrhage (IVH) is the leading cause of mortality and disability in premature neonates. The present study aimed to determine the frequency of IVH and its risk factors in the premature newborns admitted to the Neonatal Intensive Care Unit (NICU)at Fatemieh Hospital in Hamadan, Iran, in 2016. Methods & Materials This retrospective cross-sectional study was conducted on178 neonates with a gestational age of ≤ 32 weeks admitted to Fatemieh Hospital affiliated to the Hamadan University of Medical Sciences, Hamadan, Iran, in 2016. The study population was selected using the census method. The newborns were subjected to cranial ultrasound on the seventh day of life, and they were assigned into two case and control groups (namely neonates with IVH and those without IVH, respectively). Intra- ventricular hemorrhage was classified into four grades regarding Papile classification. The patients’ demographic specifications, including 1- and 5-minute Apgar scores, type of delivery, birth weight, use of mechanical ventilation, prenatal corticosteroid, gestational age, and some complications (e.g., Pneumothorax), were collected using a checklist. The data were analyzed using SPSS software version 16. Results According to the results, the prevalence of IVH in premature infants admitted to NICU was approximately 20%, and 61.2% of the neonates were male. The participants’ mean gestational age was 30.39 weeks. The comparison of delivery type between the case and control groups revealed no significant difference (P=0.197). Furthermore, there was a significant difference between the two groups in terms of their need for mechanical ventilation (P=0.03), Pneumothorax(P=0.001), and 5-minute Apgar scores (P=0.04). Moreover, the incidence of IVH had a significant relationship with the mean gestational age (P=0.001) and birth weight (P=0.04). Conclusion According to the findings, the premature newborns admitted to the NICU revealed a relatively high prevalence of IVH. The condition is aggravated in preterm neonates by some factors such as low birth weight, 5-minute Apgar score, gestational age, and the need for mechanical ventilation.


Introduction
Intraventricular hemorrhage (IVH) is one of the leading causes of mortality and disability in premature newborns, leading to motor disorder, paralysis, long-term cognitive impairment, mental retardation, and seizure [1]. Several studies conducted worldwide during the past five years have reported the incidence rate of IVH to be between 20%-40% in preterm infants. The incidence of IVH has decreased significantly over the last decade due to the global improvements in neonatal care, which seems to be because of improving practices such as the use of antenatal corticosteroids, practical resuscitation skills, appropriate handling of infants, better infrastructure, and the judicious use of ventilation (2)(3)(4)(5). However, an increase in preterm delivery resulting from the enhancement of assisted reproductive technology-mediated pregnancy has highly affected the incidence rate of IVH (3).
IVH is the extension of hemorrhage into the lateral, third, and fourth ventricles (6) and is less prevalent among full-term neonates because they have a more complex germinal matrix. IVH can emerge in the fetus, and the diagnosis of fetal IVH is based on antenatal ultrasonography and MRI. Postnatal survival is high; however, the neurodevelopmental delay is probable (7) Iran J Child Neurol. Summer 2021 Vol. 15  About 15-20% of premature newborns are exposed to IVH, and this is associated with serious complications and mortality in the absence of timely diagnosis and intervention (8). Since preterm newborns' brain is sensitive to blood pressure fluctuations, routine care measures seems to be essential among this population (9). Recently, a series of measures (namely cesarean delivery, delayed cord clamping, minimal handling of infants, avoiding head down position, midline head positioning for 72h, keeping head of the bed up at 15 -20 degrees, slow infusion of fluids, and antenatal corticosteroids for IVH prevention) have been adopted in different NICUs (2).In a study examining the effects of delayed cord clamping on IVH in preterm infants, the incidence rates of IVH and periventricular leukomalacia (PVL) were 11.43% and 5.7% in the early clamping group, respectively. In the delayed clamping group, the rate was 0%. Accordingly, they concluded that delayed cord clamping might be used as a reliable technique in reducing the IVH rate (10).
The findings of a systematic review addressing the effectiveness of head midline position in preventing the occurrence or extension of GMH-IVH in preterm infants are consistent with those dealing with the beneficial or detrimental effects of a supine head midline position and do not provide a single response to the review question (11).
Given the high complication of IVH and its high mortality rate in preterm newborns, and the lack of sufficient research in this regard, the present study aimed to determine the frequency of IVH and its risk factors in the premature neonates admitted to NICU at Fatemieh Hospital in Hamedan, Iran.

Materials &Methods
This retrospective cross-sectional study was conducted on 178 premature neonates (with a gestational age of ≤32 weeks admitted to NICU at Fatemieh Hospital affiliated to the Hamadan University of Medical Sciences, Hamedan, Iran, in 2016. The study population was selected using the census method, and patients who were discharged or died before the seventh day of birth were excluded from the study.

Study Design
The demographic data were extracted from the neonates' medical records, which encompassed gestational age, birth weight, type of delivery, use of mechanical ventilation, 1-and 5-minute Apgar scores, head circumference, Pneumothorax, thrombocytopenia, resuscitation, prescription of corticosteroid for mother before delivery, and neonatal and maternal profiles. The newborns were assigned into two case and control groups (namely newborns with IVH and those without IVH, respectively).

Statistical analysis
In this study, the independent t-test was used to compare the quantitative risk factors such as a 5-minuteApgar score, birth weight, and gestational age at birth between the two groups. Furthermore, the Chi-square test was also performed to compare the two groups in terms of qualitative variables such as type of delivery, thrombocytopenia, use of mechanical ventilation, gender, resuscitation, maternal consumption of corticosteroid before delivery, Pneumothorax, and decreased and increased blood pressure. The data were analyzed using SPSS software version 16. P< 0.05 was set as the significance level.

Ethical considerations
This study was extracted from a thesis submitted in the partial fulfillment of a requirement for the degree of MD. The present research was approved by the Ethics Committee of the Hamadan University of Medical Sciences and recorded at the clinical trial center. The confidentiality and anonymity of the participants' data were observed.

Results
According to the results of this study, 61.2% of the neonates were male, and their mean gestational age was 30.39±1.71 weeks (range: 24-33 weeks). Furthermore, the participants' mean birth weight was 1542.33±354.55 g (range: 659-2600 g). About   were more in newborns with higher degrees of IVH (18). Moreover, the probability of survival in the neonates suffering from IVH with a higher hemorrhage grade was also better than that of the newborns with lower hemorrhage grades (19). In the present study, gestational age was the main factor affecting the incidence of IVH, and this finding is in line with those of other similar studies (14,(20)(21)(22).
In some rare cases, IVH is diagnosed immediately after birth. In this regard, only 50% of newborns are diagnosed on the first-day after delivery.
Accordingly, 75% and 90% of the neonates are diagnosed in the first three days and the first week of their birth, respectively (30), while less than 5% of the newborns are diagnosed after four or five days following their birth (31). The incidence of IVH after one month of birth is a rare event; however, some patients with IVH have no clinical symptoms(6).
According to the American Academy of Neurology According to the low Apgar score, it is necessary to focus on treating neonatal resuscitation programs as a prominent IVH risk factor.